Oil and Gas Potential in Interior Alaska

Transcription

1 Oil and Gas Potential in Interior Alaska Robert F. Swenson, Deputy Director State of Alaska Department of Natural Resources Division Geological & Geophysical Surveys Alaska Department of Natural Resources

2 Sedimentary Basins of Alaska Chukchi Sea CHUKCHI Barrow Prudhoe Bay COLVILLE HOPE TAPS YUKON-KANDIK Nome SELAWIK MIDDLE TANANA Fairbanks NORTON MINCHUMINA Colorado COPPER RIVER NAVARIN HOLITNA Anchorage COOK INLET Valdez Juneau ALEUTIAN Gulf of Alaska Bering Sea NORTH ALEUTIAN KODIAK SHELF ST. GEORGE Miles

3 Working Interior Basins in Alaska I I Feel it too Jay, a strange feeling like we are going in Circles. Prudhoe Rules Cook Inlet Drools Arctic Circle Or Bust?? Kup River Kings Beluga River

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5 Nenana & Yukon Basins Nenana Basin Holitna / Minchumina

6 Exploration Risk & Resource Assessment Wide range of values = limited data/knowledge Limited subsurface data = High Risk All interior basins are currently-- High Risk Negative data verses lack of data 9 out of 10 wells in Wildcat Frontiers are economic failures Added data/knowledge = Focus of Exploration Innovative Programs Help Mitigate Risk

7 Exploration Licensing Program Issued / Awarded Licenses Bristol Bay Nenana Basin Susitna Basin Bristol Bay License: Awarded Licensee: Bristol Shores LLC Size: 329,113 Acres Copper River Basin Nenana Basin: Issued Licensee: Andex Resources Size: 483,175 Acres Susitna Basin License 1: Issued Licensee - Forest Oil Corp. 386,207 Acres Susitna Basin License 2: Issued Licensee - Forest Oil Corp. 471,474 Acres Copper River License: Issued Licensee: Forest OilCorporation Size: 318, Acres ods/pb/pg 1/05

8 Sedimentary Basins of Alaska Barrow Prudhoe Bay Chukchi Sea CHUKCHI COLVILLE HOPE TAPS YUKON-KANDIK SELAWIK MIDDLE TANANA Fairbanks NORTON Nome MINCHUMINA Nenana Basin COPPER RIVER NAVARIN HOLITNA Anchorage COOK INLET Valdez Juneau ALEUTIAN Gulf of Alaska Bering Sea NORTH ALEUTIAN KODIAK SHELF ST. GEORGE Miles Bob Swenson Deputy Director of Research Division of Geological & Geophysical Surveys Division of Oil & Gas

9 Gas Potential Interior Area DNR-DO&G 03/05

10 Using Analogous Basins to Lower Risk Nenana Basin DNR-DO&G 11/04

11 Interior Basins Tertiary Stratigraphy Cook Inlet / Susitna/ Mat Valley Tanana / Holitna / Minchumina Yukon Flats

12 Tertiary Basin Depositional Systems Flood Plain & Channel Abd. Point Bar Channel Fill Crevasse Splay

13 Usibelli Group in Outcrop Belt South of Nenana Exploration License Area Roy D. Merritt, DGGS 08/95

14 Tertiary Reservoir Section > 25,000 Ft Recent Discoveries/ Developments

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16 Sand Distribution in a Fluvial System

17 Nenana Basin Thickness of Sedimentary Basin (Tertiary) Contour Interval = 2,000 Ft. ods 2/02

18 Nenana Basin Stratigraphic Sections SOUTH NORTH North Flank Alaska Range ARCO Totek Hills #1 Unocal Nenana #1 Deep Nenana Basin (Possible, but undrilled) Nenana Gravel Surface Eroded (Qs) (Qs) (Plio.) Eroded (Plio.) (Plio.) (M.Mio.) Lacustrine Shales (Plio.) Usibelli Group (E.Mio.) (M.Mio.) Volcanics Cantwell Fm. Sediments v v v v v v v v (Paleoc.) (Eoc.) (L. Cret.) Gravel, Sand, Silt and Clay Conglomerate and Coarse Sandstone Lacustrine / Marine Shales (Qs) (Plio.) (M.Mio.) (E.Mio.) (Eoc.) (Paleoc.) Surficial Deposits Pliocene Middle Miocene Early Miocene Eocene Paleocene vv v vvv Non-Marine Conglomerate, Sandstone, Mudstone, Coal and Minor Tuft Lacustrine / Alluvial Fan Sequence Volcanics Base of Nenana Basin?? (Paleoc.) 10,000 Ft. From C.E. Paris, 1999 (L.Cret.) Late Cretaceous Unconformity Metamorphic Basement Oblique Slip Faults? 20,000 Ft.

19 Nenana Exploration License Area with Seismic Survey Area DO&G 03/05

20 Nenana Basin Oil & Gas Potential Andex Resources, LLC, holds a 7-year Exploration License for 482,942 acres with a $2.5MM work commitment. License expires September Tertiary-age alluvial basin covering 8,500 square miles and up to > 18,000 feet deep in its northern area. Potential for coal bed methane and conventional natural gas is good. Good reservoir rocks are associated with thick coal seams. Deep source and reservoir rocks and geothermal history are conducive for formation and entrapment of conventional natural gas. Tertiary sedimentary section is time-equivalent to Cook Inlet s productive Kenai Group. Potential for oil is low due to thin low-organic source rocks. With only limited G&G data the basin is under-explored and poorly understood: Unocal Nenana #1 (1962) 3,062 deep, coal seam gas shows. ARCO Totek Hills #1 (1984) 3,590 deep, coal seam gas shows. 350 miles 2-D seismic data in southern and central basin areas ( ). Gravity coverage across entire basin. Both the overall size and different tectonic history (post depositional) limits ability to draw analogies Current exploration effort will greatly enhance our knowledge of the resource potential, and may lead to development.

21 Nenana & Yukon Basins Nenana Basin Holitna / Minchumina

22 Texa co Yukon Flats Basin Beav er Beaver Sub- Basins 5,000 YP88-4 Kaltag-Porcupine Fault Zone 5,000 10, , ,00 0 Birc h Cree k Venetie Sub- Basin 10,00 0 Texa co 5,000 Fort Yukon YP 88-3 North YP88-2 5,000 Basin Fill Thickness Seismic Survey (Exxon/Amoco) Seismic Survey (Texaco) Doyon Lands YP88-2 Tintina Fault Zone YP Miles 0' 5,000 10,000 15,000 20,000 25,000 SW Structural Traps Post Extensional Sag Post Extensional Infill Extensional Phase? Miocene Pliocene Coal Series Eocene Oligocene Fluvial Sequence Paleocene - Oligocene Lacustrine / Alluvial Fan Sequence? YP 88-2?? NE Miles Horizontal Scale Extensive, strong amplitude, high frequency reflectors Extensive, strong amplitude, low frequency reflectors From Chet Paris Local, strong amplitude, low frequency reflectors Coarse clastic wedge

23 Summary Interior Alaska sedimentary basins have clear potential for gas accumulations Currently, the available subsurface information is very limited All interior basins could be considered high risk because of this lack of data Data gathering and exploration is needed in all interior basins to characterize resource potential The Nenana Basin exploration program is critical to that effort and could discover a viable resource for providing an alternate energy source for residents of interior Alaska